Production of wear-resistnat cloth and buffing wheel made of the same



y 29, 1956 A. 5. BROWN ET AL 2,

PRODUCTION OF WEAR-RESISTANT CLOTH AND BUFFING WHEEL MADE OF THE SAME Filed June 5, 1951 Fig. 1 Fig. 2

Alfred S. Brown Angus M. Brown INVENTORS New AH'Qrney United States Patent PRODUCTION OF WEAR-RESISTANT CLOTH AND BUFFING WHEEL MADE OF THE SAME Alfred S. Brown, Hamilton, and Angus M. Brown, Utica, N. Y., assignors to Divine Brothers Company, Utica, N. Y., a corporation of New York Application June 5, 1951, Serial No. 229,977

17 Claims. (Cl. 51-297) The present invention relates to buffing wheels of the cloth type, and to the treatment of cloth for the manufacture of buffing wheels and for other purposes.

The cloth used in buffing wheels is subject to severe requirements which are different in many ways from those met in any other fields where cloth is used. To produce an economical and long lasting bufiing wheel, it is not merely a question of increasing the wear resistance of the cloth against the effects of mechanical abrasion. True, such wear resistance is one factor, but there must also be considered the factors of having the cloth properly retain the grit or buffing compound, having it present the compound to the work in the most effective manner, and also having the cloth, in its treated form, compatible to the proper degree with the buffing compound, and preferably with different types of buffing compound, such as a grease base compound, and a greaseless compound. In addition to these requirements, any treatment imparted to the buffing wheel cloth to enhance the performance of the buff should, at the same time, not cause deleterious effects in other directions. For example, any treatment imparted to the cloth should not cause swelling or coating of the fibers to such an extent as to reduce the interstices between the strands or threads to such an extent as to interfere appreciably with the flow of air through the cloth, which is necessary for cooling purposes during high speed operation.

An object of the present invention is to produce a generally improved and more satisfactory bufling wheel which fulfills to a reasonable degree all of the many requirements for such a wheel.

Another object is the provision of a buffing wheel which not only has appreciably longer life than comparable wheels of the prior art, but also is more economical in the use of buffing compound than comparable wheels of the prior art.

Still another object of the invention is the provision of a buffing wheel having greatly increased life and greatly increased wearing ability as compared with prior wheels and which, at the same time, has a properly balanced afiinity for or compatibility with bufiing compounds both of the grease type and of the greaseless type.

A further object of the invention is the provision of a commercially practical treatment for cloth, which treatment results in a cloth having greatly improved characteristics when used in bufling wheels, these characteristics of the treated cloth being useful and beneficial also in other fields as well as in buffing wheels.

These and other desirable objects may be attained in the manner disclosed as an illustrative embodiment of the invention in the following description and in the accompanying drawings forming a part hereof, in which:

Fig. 1 is a diagrammatic face View of a bufiing wheel 7 in accordance with one embodiment of this invention; and

Fig. 2 is a diagrammatic cross section taken diametricallythrough the same.

The same reference numerals throughout the several views indicate the same parts.

As above indicated, the present invention deals with the treatment of cloth and with the use of the treated cloth in bufiing wheels primarily, although it is useful elsewhere also. The mechanical construction of the buffing wheel (other than the characteristics of the cloth) is wholly immaterial for purposes of the present invention. Thus it is immaterial whether the layers of cloth making up the buffing wheel be sewn together or fastened in any other manner; whether, if sewn, they be sewn radially, concentrically, spirally, or otherwise; whether the cloth plies extend radially inwardly all the way to the central shaft or arbor of the bufiing wheel or whether a core or hub of cardboard, metal, or other non-cloth material is used; or whether the bufling wheel face be wide or narrow, or the diameter be great or small, or whether the wheel be solid or be provided with ventilating holes. Since all of these factors have no substantial bearing on the present invention, the present drawings merely show one possible form of bufiing wheel in a diagrammatic or schematic manner, which wheel comprises a multiplicity of plies of fabric 3 held to each other in any suitable way, the plies having a central arbor hole 5 by means of which they are mounted upon a rapidly rotating arbor or shaft, and having a substantially cylindrical peripheral surface 7 which constitutes the working surface of the bufi'ing wheel. It must be understood, however, that the fabric plies may be arranged, held to each other, and mounted in any other suitableway, as for example the way shown in U. S. Patent 2,531,249, issued November 21, 1950, to the assignee of this present application, or in any other suitable manner known in the art.

The treatment of the present invention may be applied to any type, kind, or weight of cloth suitable for making buffs, such cloths being well known in the buff art. Preferably, the treatment is applied to unbleached cotton sheeting of the kinds customarily used for buffs. It has been successfully used, for example, in treating unbleached cotton sheeting having thread counts varying from 64 x 64 to the inch to 86 x 93 to the inch, and having weights (in 40 inch width) varying from 3.15 yards to the pound, to 2.60 yards to the pound. But these figures are given as typical examples, rather than as limitations.

Before starting treatment of the present invention, the textile fabric is preferably reduced by well known processes to the state known as boiled fabric, meaning thereby that any sizes, starches, gums, or other additives which have been used by the textile mill in sizing or treating the threads, are removed by boiling or otherwise.

The present invention, starting preferably with the boiled fabric stage, treats this fabric with an aqueous solution of one or more glycols to serve the functions of a binding agent, a lubricant, and a humectant, while at the same time being compatible with the cellulosic materials of which the textile fabric is made. Preferably two glycols are used in the treating solution, one glycol having a relatively high degree polymerization and serving as a yieldable binding agent, the other glycol having a substantially lower degree of polymerization and serving as a lubricant and humectant. It is, of course, necessary that the two glycols be compatible with each other as well as with the cellulosic material of the textile fabric, and that they be readily available at a reasonable price. They should also have the desired degree of compatibility with the buffing compound to be used, which desired degree means, in some cases, that they should be mildly incompatible with the buffing compound, in order to tend to prevent the buffing compound from traveling radially f inwardly from the base of the wheel toward the center, and thus keep the compound on the working face of the wheel.

In addition to the above mentioned requirements, the glycols selected for this treatment should also be water soluble, so that the treatment may be applied by means of an aqueous solution, Without the necessity for other solvents which may be more troublesome, more expensive, or dangerous.

Excellent results have been obtained by using, as the F higher polymerization glycol, the polyethylene glycol polymerized to an approximate average molecular weight o f about 6000 to 7500 and readily available on the market under the designation Carbowax compound 6000, and by using as the lower polymerization glycol, the polyethylene glycol polymerized to an approximate average inoleculanweight at'about 400 and readily available on themarket under' the name polyethylene glycol 400. Thus the designating numbers 6000 and 400 indicate approximate'average molecular weights, as well understood in the art and as disclosed, for example, on page of the printed catalog Synthetic Organic Chemicals, issued by Carbide and Carbon Chemicals Corporation, twelfth edition, second printing, published 1946.

As already indicate an aqueous solution of these two glycols'isformed'coiitaining preferably about 4% of the Carbowax compound 6000, and about 3% of the polyethylene glycol 400, the balance being water except for suitable neutralizers, if needed. The textile fabric,-prefrably 'in the boiled state as above mentioned, is run th'rdughthis aqueous solution, then removed therefrom and dried, preferably by the drying process well known in the'textile field as tenter drying. While so-called normal tension may conveniently be maintained on the weft strands of the fabric during drying, it is not essential that th'i's'be "done, as there is no particular harm in slight shrinkage of the weft strands during drying, particularly ifthe fabric is to be used in buff manufacture. 'Upon completion of drying, the fabric is ready to be used for making into buffing wheels, or for other uses in which the characteristics imparted to these fabrics by this treatment'may be beneficial. When used for buffing wheels, the treated and dried fabric may be cut, folded, sewed or otherwise secured, and mounted in any conventional or known manner, as for example in the manner disclosed in said U. '8. Patent 2,531,249, or in the simple superimposed disk manner indicated diagrammatically in the drawings ofthepresent application, or in any other desired manner. Thetreating bath should be kept approximately neutral, although it is not essential that it be kept at a pH value of exactly 7.0. However, it should not be allowed to become'either strongly acidic or strongly basic, as either condition'might tend to weaken the fibers of the cloth being treated. It should be kept within the limits of pH '6 to 8, and preferably within the narrower limits of 7.0 to 7.5 {in other'words, slightly basic if not neutral. Continuing use of the bath in treating fabric usually causes the treating bath to become slightly acidic, and this should be corrected from time to time by the addition of any suitable neutralizer. "As for the amounts of the glycols in the treating bath, the lower limit on the amount of the higher polymerized glycol is determined by the necessity of using enough of this material to add a significant amount to the cloth as the cloth passes through the treating bath. The upper limit thereof is set by three factors: (1) There should not be so much of this material used that it will materially swell the fabric strands or threads to such extent as to close the interstices between the strands so as to interfere (.under actual buff operating conditions) with the passage of ventilating air through the fabric. (2) There should not be so much used that there is likely to be a bulk movement of the material in or on the cloth, under the influence of the'centrifugal forces encountered in actual buff operation. (3) There should not be so much used that it will stiffen the fabric excessively for its intended use. There is, of course, also the further factor that the economics of the situation aifect the upper limit of the higher polymerized glycol material; in other words, when enough of the material is present to perform its intended function, the use of any greater amount is an economic waste. When the higher polymerized glycol is the above mentioned preferred material (Carbowax compound 6000) the proportion thereof used in the treating bath may vary between the limits of about 2% and 8%. Preferably it is about 4% as already mentioned. 7 i

The glycol of lower polymerization has a considerably lower viscosity than the glycol of higher polymerization and thus serves to lower the viscosity of the mixture to the point where it will penetrate or impregnate the cloth rather than undesirably depositing semi-solid masses or globules of the glycols on the cloth. This is, of course, in addition to its previously mentioned function as a lubricant and humectant. But there should be a proper balance between the amount of lower polymerized glycol and the amount of higher polymerized glycol so that the viscosity is not made so low that the treating material remaining on the fabric, after drying, will flow outwardly through the bufiing wheel due to the centrifugal action when the wheel is rotated. In order to avoid too great a lowering of the viscosity, it is desirable that the lower polymerization glycol be used to a somewhat lesser amount than the higher polymerized glycol. Thus when the lower polymerization glycol is the preferred material above mentioned (polyethylene glycol 400) then the amount thereof in the treating bath may conveniently vary between the limits of about 1% to 6%, in each case being a percentage somewhat smaller than that of the higher polymerization glycol, and preferably being about 3% of polyethylene glycol 400 when Carbowax compound 6000 is used to the extent of about 4%.

This mixture of Carbowax compound 6000 and polyethylene glycol 400 gives very excellent results. This mixture appears to be slightly incompatible with the grease which is commonly used in bufling compounds of the grease base type, and this slight incompatibility is very beneficial because it tends to keep the buffing compound at the face of the wheel and prevent it from spreading inwardly toward the center. The grease apparently does not have as great an afiinity for the grit as is generally supposed. So if the cloth is treated in a way to'make it compatible with the grease, the cloth will tend to drain the grease away from the grit, with the result that the grit is loosened from the face of the wheel and no longer performs its function, and more buffing compound must soon be added. But this is avoided by the present process, wherein the cloth is made slightly incompatible with the grease, so that the grease has now a greater affinity for the grit than it has for the cloth, and the grease tends to remain on the face of the wheel to perform its function of holding the grit in place in proper operating position. Thus'the consumption of bufling compound is reduced.

On the other hand, in the so-called g'reaseless typeof buffing compound, sometimes and more properly called a glue base compound, the glue appears to have too great an aflinity for the grit and it would be desirable to tend to draw some of the glue away from the grit. The cloth treatment of the present invention has the happy faculty of having afiinity for or compatibility with the glue used in this type of buffing compound, so that the glue tends, quite desirably, to move into the buffing wheel, thus somewhat reducing the undesirably great tenacity with which the glue holds the grit, and thus making the grit more effective.

It is not essential that the glycol of high degree of polymerization and the glycol of low degreeof polymerization both be polyethylene glycols. Either or both of them maybe glycols of other kinds, as for example polypropylene glycols. For example, the glycol of higher degree of polymerization may be polypropylene glycol 2025, and the glycol of lower degree of polymerization may be polypropylene glycol 425, both of these materials being used in approximately the same percentage ranges respectively above mentioned for the polyethylene glycol of higher degree of polymerization and the polyethylene glycol of lower degree of polymerization.

Remarkable results have been achieved by the use of this invention. The wear resistance and useful life of the bufling wheel have been very greatly increased (often two or three times or more) as compared with a similar buffing wheel made of cloth similar in every respect except not being treated according to the present invention. In addition, buffing wheels made of cloth treated according to the present invention are found in actual tests to use much less buffing compound, for performing a given amount of work, as compared with wheels similar in all respects except made of cloth which is not treated according to the present invention. Hence the cloth treatment of the present invention results in a cloth which produces greatly improved and distinctly superior bufiing wheels, and which is useful also in other fields wherever increased wear resistance of cloth is desirable, with or without the other features which make this cloth particularly adapted for buffs, such as the features of affinity for glue and slight incompatibility with grease.

The various explanations above given as to the theory of operation are offered as tentative hypotheses helping :to explain, at least in part, the remarkably superior results achieved by the present invention. The invention is not intended to be limited to or by any particular theory of operation.

It is seen from the foregoing disclosure that the above mentioned objects of the invention are well fulfilled. It is to be understood that the foregoing disclosure is given by way of illustrative example only, rather than by way of limitation, and that without departing from the inven tion, the details may be varied within the scope of the appended claims.

What is claimed is:

l. A buff having a relatively high degree of wear resistance, comprising a plurality of plies of woven textile fabric arranged in side by side relation and collectively having an approximately cylindrical peripheral working face, each of said plies of fabric being impregnated throughout substantially its entire mass with a mixture of a substantial quantity of polyethylene glycol having a molecular weight in the neighborhood of 400 and a substantial quantity of polyethylene glycol having a molecular weight in the neighborhood of 6000, the glycols in the impregnating mixture being in the proportion of not less than one part and not more than two parts of said glycol having a molecular weight in the neighborhood of 6000 to each one part of said glycol having a molecular weight .in the neighborhood of 400.

2. A buff having a relatively high degree of wear re- ;sistance, comprising a plurality of plies of woven textile fabric arranged in side by side relation and collectively having an approximately cylindrical peripheral Working :face, each of said plies of fabric being impregnated 1 throughout substantially its entire mass with a mixture of 2 the following polyethylene glycols in approximately the following proportions, viz: three parts of polyethylene ;glycol having an approximate average molecular weight .in the neighborhood of 400 and four parts of polyethylene glycol having an approximate average molecular .weight in the neighborhood of 6000.

3. A buff having a relatively high degree of wear resistance, comprising a plurality of plies of woven textile :fabric arranged in side by side relation and collectively "having an approximately cylindrical peripheral working :face, each of said plies of fabric being impregnated :throughout substantially its entire mass with a mixture of .the following polyethylene glycols in approximately the ifollowing proportions, viz: three parts of polyethylene glycol having an approximate average molecular weight in the neighborhood of 400 and four parts of polyethylene glycol having an approximate average molecular weight in the neighborhood of 6000 to 7500.

4. A buff having a relatively high degree of wear resistance, comprising a plurality of plies of woven textile fabric arranged in side by side relation and collectively having an approximately cylindrical peripheral working face, each of said plies of fabric being impregnated throughout substantially its entire mass with a residue of polyethylene glycols remaining after immersing said fabric in an aqueous solution containing about three per cent of polyethylene glycol having a molecular weight in the neighborhood of 400 and about four per cent of polyethylene glycol having a molecular weight in the neighborhood of 6000 and about ninety-three per cent of water, and then drying said fabric after removal from said aqueous solution.

5. A buif having a relatively high degree of wear resistance and a desirable degree of compatibility with buifing compounds applied to the working face of the buff, said buff comprising a plurality of plies of woven textile fabric arranged in side by side relation and col- .lectively having an approximately cylindrical peripheral working face, each of said plies of fabric being impregnated throughout substantially its entire mass with a glycol residue remaining in the fabric after immersion of the fabric in and removal of the fabric from an aqueous solution containing not less than eighty-six per cent of water and not more than a total of fourteen per cent of a mixture of two glycols, one being a polymerized glycol having an average molecular weight of less than about 425 and the other being a polymerized glycol having an average molecular weight of more than about 2000, the impregnation of said glycols in said fabric being to prepare the buif for receiving a conventional bufling compound on the working face of the buff and not being a substitute for such buffing compound.

6. A buif in accordance with claim 5, in which said glycol having an average molecular weight less than about 425 is polyethylene glycol having an average molecular weight of about 400.

7. A buff in accordance with claim 5, in which said glycol having an average molecular weight more than about 2000 is polyethylene glycol having an average molecular weight of about 6000 to 7500.

8. A buff in accordance with claim 5, in which said two glycols are polyethylene glycol having an average molecular weight of about 400 and polyethylene glycol having an average molecular weight of about 6000 to 7500.

9. A buff in accordance with claim 5, in which said two glycols are polypropylene glycols.

10. A buff in accordance with claim 5, in which at least one of said two glycols is polypropylene glycol.

11. A butt in accordance with claim 5, in which at least one of said two glycols is polyethylene glycol.

12. As a new article, a liquid bath for immersion of woven textile fabric to increase the wear resistance of the fabric, said bath being composed essentially of not less than about eighty-six per cent of water, from one to six per cent of polyethylene glycol having an average molecular weight of about 400, and from two to eight per cent of polyethylene glycol having an average molecular weight of about 6000 to 7500.

13. As a new article, a liquid bath for immersion of woven textile fabric to increase the wear resistance of the fabric, said bath being composed essentially of not less than about eighty-six per cent of water, from one to six per cent of polyethylene glycol having an average molecular weight of about 400, from two to eight per cent of polyethylene glycol having an average molecular weight of about 6000 to 7500, and a neutralizer acting as means to keep said bath at a pH value substantially in the range 7.0 to 7.5.

14. As a new article of manufacture, wear-resistant fabric comprising a fabric body impregnated throughout substantially its entire mass with that amount of glycol material remaining in the fabric when the fabric is immersed in and removed from an aqueous bath composed essentially of water containing from about one to six per cent of a polymerized glycol having an average molecular weight of less than about 425 and from two to eight per cent of a polymerized glycol having an average molecular Weight of more than about 2000.

15. As a new article of manufacture, wear-resistant fabric comprising a fabric body impregnated throughout substantially its entire mass with that amount of glycol material remaining in the fabric when the fabric is immersed in andremoved from an aqueous bath composed essentially of water containing from about one to six per cent of polyethylene glycol having an average molecular weight of about 400 and from two to eight per cent of polyethylene glycol having an average molecular .weight'of about 6000 to 7500.

16. As a new article of manufacture, wear-resistant fabric comprising a fabric body impregnated throughout substantially its entire mass with that amount of glycol material remaining in the fabric when the fabric is immersed in and removed from an aqueous bath composed essentially of water containing about three per cent of :0 polyethylene glycol having .an average molecular weight of about 4400 and about four per cent of polyethylene glycol having an average molecular weight of about 6000 to 7500.

17. The method of making a buff which comprises the steps of providing a textile fabric, immersing the fabric in a liquid bath having substantially the composition defined in .claim 13, removing the fabric from said bath, drying the fabric, cutting the fabric and placing a plurality of plies of the fabric in side by side relation collectively forming an approximately cylindrical Working face, and applying buffing compound to said working face.

References Cited in the file of this patent UNITED STATES PATENTS 1,374,018 Levett Apr. 5, 1921 1,728,585 Yerges Sept. 17, 1929 2,331,583 Twyning Oct. 12, 1943 2,436,128 Twyning et a1. Feb. 17, 1948 2,457,229 Hanford et al Dec. 28, 1948 2,486,024 Hearne et al Oct. 25, 1949 2,520,733 Morris et al. Aug. 29, 1950 2,649,362 Fowler Aug. 18, 1953 

1. A BUFF HAVING A RELATIVELY HIGH DEGREE OF WEAR RESISTANCE, COMPRISING A PLURALITY OF PLIES OF WOVEN TEXTILE FABRIC ARRANGED IN SIDE BY SIDE RELATION AND COLLECTIVELY HAVING AN APPROXIMATELY CYLINDRICAL PERIPHERAL WORKING FACE, EACH OF SAID PLIES OF FABRIC BEING IMPREGNATED THROUGHOUT SUBSTANTIALLY ITS ENTIRE MASS WITH A MIXTURE OF A SUBSTANTIAL QUANTITY OF POLYETHYLENE GLYCOL HAVING A MOLECULAR WEIGHT IN THE NEIGHBORHOOD OF 400 AND A SUBSTANTIAL QUANTITY OF POLYETHYLENE GLYCOL HAVING A MOLECULAR WEIGHT IN THE NEIGHBORHOOD OF 6000, THE GLYCOLS IN THE IMPREGNATING MIXTURE BEING IN THE PORPORTION OF NOT LESS THAN ONE PART AND NOT MORE THAN TWO PARTS OF SAID GLYCOL HAVING A MOLECULAR WEIGHT IN THE NEIGHBORHOOD OF 6000 TO EACH ONE PART OF SAID GLYCOL HAVING A MOLECULAR WEIGHT IN THE NEIGHBORHOOD OF
 400. 